The inventor is aware of several types of connector blocks, first of which is a simple single channel connector block wherein a channel open at one end thereof for the insertion of a detonator is used and side walls of shock tubes to which the signal is to be propagated are brought into close proximity of the closed end of the channel so that when the detonator detonates, the shockwave of the detonation fractures the shock tube side wall and propagates the signal along the shock tubes. This is sometimes known as a C-clip or G-clip arrangement. This type of connector block only works with detonators and has other geometric limitations.
A second type connector block is described international patent WO2009076682 to the same inventor, which there is provided a multi-port transmission line connector having a body which has at least four ports and channels therein for connecting one final transmission line with multiple signal transmission lines in a blasting system or transferring blasting signals, the at least four ports having a bore there through, wherein in at least one of the ports is located an inner sleeve of deformable material and located between the inner sleeve and the body a crimpable secondary sleeve such that, in use, when a shock tube has been inserted into the port and passes through the inner sleeve portion of the secondary sleeve crimped thereby to deform the inner sleeve and to seal against the shock tube thereby retaining the shock tube in position and inhibiting the ingress of water into the connector through said port. This type of connector block has advantageous over the prior connector blocks but through its multi-dimensional structure is costly to produce.
The inventor thus identified a need for a multi-port connector block with the advantageous the block WO2009078682 while simplifying manufacture and reducing the costs thereof.